WO2023194384A1

WO2023194384A1 - Charging infrastructure, vehicle contact unit, system and method for producing a conductive connection

Info

Publication number: WO2023194384A1
Application number: PCT/EP2023/058853
Authority: WO
Inventors: Friedrich Lobenstock; Fabian Luttenberger; Thomas Schanzer; Sebastian Lassacher
Original assignee: Easelink Gmbh
Priority date: 2022-04-04
Filing date: 2023-04-04
Publication date: 2023-10-12

Abstract

The invention relates to a charging infrastructure (12) for producing a conductive connection with a vehicle contact unit (16). The charging infrastructure (12) has a ground contact unit (18), which has a plate-type main body (26) and multiple contacts (30), which are arranged on a charging surface (28) of the main body (26), with which the vehicle contact unit (16) can come into contact. The multiple contacts (30) comprise at least one protective conductor contact (36), power contacts (32) and at least one control contact (40) for detecting a contacting. The at least one protective conductor contact (36) is hard wired. The power contacts (32) are associated with at least one potential layer (34). The at least one control contact (40) is formed separately from the power contacts (32) and separately from the at least one protective conductor contact (36). The invention also relates to a vehicle contact unit (16), a system (10) and a method for producing a conductive connection.

Description

Charging infrastructure, vehicle contact unit, system and method for establishing a conductive connection

The invention relates to a charging infrastructure for establishing a conductive connection with a vehicle contact unit. The invention further relates to a vehicle contact unit for establishing a conductive connection with a ground contact unit. In addition, the invention relates to a system for establishing a conductive connection. The invention further relates to a method for establishing a conductive connection between a ground contact unit and a vehicle contact unit.

In the case of at least partially electrically powered vehicles, such as plug-in hybrid vehicles and purely electric vehicles, the vehicle batteries must be charged regularly, preferably after each journey. For this purpose, the vehicle is connected to a corresponding power source, usually using a plug, for example a so-called type 2 plug, which must be manually plugged into a corresponding socket on the vehicle by a person. This also ensures that the plug is guided so that contact is made in a defined manner.

From the prior art, for example WO 2019/052962 A1, ground contact units for vehicle battery charging systems that are provided on the ground are also known. The ground contact units can automatically establish a conductive connection with a corresponding vehicle contact unit provided on the vehicle to be charged in order to charge the vehicle. The vehicle contact unit can be provided on the underbody of the vehicle, moving downwards in order to establish electrical contact with the ground contact unit.

For example, the ground contact unit is designed as a so-called matrix charging pad, as shown in WO 2019/052962 A1. For this purpose, the ground contact unit includes a large number of contacts, which are matrix-like are arranged, wherein the contacts can be contacted by means of the vehicle contact unit in order to establish an electrical connection between the ground contact unit and the vehicle contact unit.

It can be provided that the vehicle contact unit is precisely aligned with respect to the ground contact unit before a connector of the vehicle contact unit contacts the ground contact unit at a defined point. Alternatively, it can be provided that no guidance is provided for the vehicle contact unit and/or no precise contacting, in which case a contact point of the connector of the vehicle contact unit on the ground contact unit must be detected. Depending on the placement point, the correspondingly occupied contacts of the ground contact unit are switched on in order to establish the electrical connection via these contacts.

However, the methods for detecting the landing point known from the prior art are complicated and involve high costs.

In this respect, the object of the invention is to provide a cost-effective way of detecting contact.

The object is achieved according to the invention by a charging infrastructure for establishing a conductive connection with a vehicle contact unit. The charging infrastructure includes a ground contact unit that has a plate-shaped base body and a plurality of contacts that are arranged on a loading surface of the base body, against which the vehicle contact unit can come into contact. The multiple contacts include at least one protective conductor contact, power contacts and at least one control contact for detecting contact. The at least one protective conductor contact is hard-wired. The power contacts are assigned to at least one potential level. The at least one control contact is designed separately from the power contacts and separately from the at least one protective conductor contact.

Furthermore, the object is achieved according to the invention by a vehicle contact unit for establishing a conductive connection with a ground contact unit. The vehicle contact unit has several contacts that can come into contact with a loading surface of the ground contact unit. The vehicle contact unit is translational and/or rotational in one direction Loading area can be moved on a parallel plane. The multiple contacts include at least one protective conductor contact, power contacts and at least one control contact for detecting contact. The at least one protective conductor contact is hard-wired. The power contacts are assigned to at least one potential level. The at least one control contact is designed separately from the power contacts and separately from the at least one protective conductor contact.

The basic idea of the invention is to detect contacting of the ground contact unit or the vehicle contact unit when establishing the conductive connection by providing a separately designed control contact through which a control signal can be passed, whereby it is determined whether there is contact between the vehicle contact unit and the ground contact unit is present, i.e. a conductive connection. The control contact is designed separately from the power contacts and separately from the at least one protective conductor contact, so that a dedicated control signal can be used to detect the corresponding contact. In other words, the control signal is not a modulation or a high-frequency property of a signal that is provided and evaluated via one of the power contacts, but rather a dedicated control signal. However, it is conceivable that the control signal is a signal that is related to the protective earth (PE), i.e. PE-related.

Basically, the at least one protective conductor contact is hard-wired, which means that the corresponding protective conductor contact always serves as a protective conductor. It is therefore not possible for the protective conductor contact to be connected to a potential level intended for charging the vehicle, whereby the protective conductor contact could function as a power contact.

It can be provided that the respective power contacts are assigned to the at least one potential level via at least one contact switch, which makes it possible to switch the individual power contacts potential-free. This is the case, for example, if not all power contacts contribute to the conductive connection when contacting is made. The corresponding power contacts, which are not just conductive connections contribute, can therefore be switched potential-free via the contact switches.

One aspect provides that at least two power contacts are assigned to the same potential level. In this respect, more than one power contact is provided per potential level. The multiple power contacts that are connected to a potential level therefore represent a power contact level. The respective power contacts of a power contact level can be connected in groups to different potential levels by providing a corresponding switching unit. The switching unit can be set up to selectively connect power contacts of a first power contact level to a first potential level or a second potential level. In this respect, all power contacts of a power contact level can be connected to a selected potential level via the switching unit. However, it is not possible to connect individual power contacts of an assigned power contact level with different potential levels. Furthermore, it can also be provided that power contacts of different power contact levels are not connected to a common potential level.

In particular, several potential layers are provided, with at least two power contacts being assigned to each potential layer. For example, two potential layers or four potential layers are provided. This depends on whether, for example, it is a direct current application (“DC application”) or an alternating current application (“AG application”), in particular a three-phase current application. With four potential positions, these can be formed by a neutral position (N) and three phase positions (L1, L2, L3).

A further aspect provides that the charging infrastructure includes a monitoring circuit that is set up to monitor the contacting of the at least one control contact. In particular, the monitoring circuit can be set up to determine a placement position of the vehicle contact unit. The detection of the contact merely ensures that there is contact with the vehicle contact unit somewhere on the loading surface of the ground contact unit, which can be determined accordingly by the monitoring circuit, which does this via the control contact current control signal is detected. For this purpose, all control contacts are supplied with a control signal in a simple manner, with a continuous connection via one of the control contacts being recognized during contacting. However, it is not yet possible to determine the placement position, i.e. where the vehicle contact unit contacts the ground contact unit.

However, the monitoring circuit can also be set up to determine the placement position of the vehicle contact unit on the loading area of the ground contact unit. This means that the position on the ground contact unit, in particular the loading area, at which the vehicle contact unit contacts the loading area can be determined. This is possible, for example, by applying the control signal to the control contacts individually or in groups in order to first determine a rough area on the loading area of the ground contact unit. Theoretically, the control contacts could also be subjected to different control signals, with an evaluation of the control signal of the continuous connection then allowing a conclusion to be drawn about the placement position of the vehicle contact unit.

When monitoring by means of the monitoring circuit, it can also be determined whether there is a displacement of the vehicle contact unit relative to the ground contact unit and/or a rotation about an axis perpendicular thereto, which results in a termination of a control contact connection, i.e. the connection via the at least one control contact.

In particular, the at least one control contact and the power contacts are designed in such a way that the connection via the at least one control contact is first broken off before the connection via the power contacts is broken off. This makes it possible for the monitoring circuit, which detects that the connection is broken via the control contact, to control a shutdown device so that the corresponding power contacts are switched potential-free before the connection is broken via the power contacts. This effectively prevents arcs or other effects that should be avoided.

The tearing of the conductive connection can be detected in particular in a direction that is perpendicular to the contacting direction, i.e. in the plane in which the contacting is present. It is determined whether the Vehicle contact unit slips or shifts relative to the ground contact unit, as a result of which the connection via the at least one control contact can be broken.

The shutdown device can include a main switch, for example a contactor. The main switch can then be opened to create galvanic isolation. Alternatively or additionally, the shutdown device can include an electronic power control that reduces the applied potential to a non-critical value.

In other words, activating the shutdown device corresponds to error protection, since the state of the contact switches is checked, with the main switch being opened in the event of a fault in order to switch the contacts potential-free and/or the value of the applied potential being reduced. Alternatively or additionally, this is done if the existing contact suddenly breaks off or is not terminated in a controlled manner.

In principle, the monitoring circuit can be provided as part of the charging infrastructure or in the vehicle, so that the corresponding monitoring can also be carried out on the vehicle side.

For example, the at least one control contact has a smaller area than the at least one protective conductor contact and/or than one of the power contacts, in particular than each of the power contacts. This ensures that when the vehicle contact unit is displaced relative to the ground contact unit, the connection established via the at least one control contact is first torn off before the connection via the power contacts and/or the connection via the protective conductor contact is torn off. In this respect, the power contacts can be actively switched to potential-free before their connection breaks and/or an arc occurs.

According to a further aspect, the plurality of contacts include at least two control contacts, so that the charging infrastructure is set up to detect a contacting orientation of the vehicle contact unit on the loading area by means of the at least two control contacts. In particular, the plurality of contacts include two categories of control contacts that differ in terms of control signals used that are passed through the control contacts become. For example, the control signals are inverted to one another and/or have different signal shapes so that they can be distinguished from one another. Electrical errors such as short circuits or shunts can be reliably detected. It can also be provided that the corresponding control signals, which run via the at least two different control contacts, are generated at a time offset from one another, as a result of which no valid signal would be generated in the event of any short or shunt circuits. In principle, due to the at least two control contacts, which are located in a contact area which is formed when the conductive connection between the vehicle contact unit and the ground contact unit is established, it can be ensured that the relative orientation of the vehicle contact unit to the ground contact unit can be determined. Based on the determined orientation, the power contacts can then be connected to corresponding potential positions in order to provide an interconnection of the power contacts that is coordinated with respect to the determined relative orientation.

In addition, the at least one protective conductor contact can be formed by a continuous surface which provides a protective conductor level which is broken through by the power contacts and/or the at least one control contact. The corresponding protective conductor level is also referred to as the PE level (“PE plane”). In other words, a connection surface, for example a loading surface of the ground contact unit, can be formed largely by the protective conductor contact, with the corresponding power contacts being arranged in the plane formed by the protective conductor contact, in particular with an annular insulating area in order to protect the power contacts from the protective conductor. Contact, i.e. the corresponding protective conductor level, to be electrically isolated. Likewise, the control contact can be electrically insulated from the protective conductor level with an annular insulating area.

One aspect provides that the contacts are designed such that the at least one control contact loses contact with the ground contact unit earlier than the power contacts and/or the at least one protective conductor contact during a relative movement of the vehicle contact unit to the ground contact unit. Alternatively or additionally, the at least one protective conductor contact in the event of a relative movement of the vehicle contact unit to the ground contact unit later than the power contacts lose contact with the ground contact unit. For example, the at least one control contact is smaller and/or shorter or has a smaller spring travel than the power contacts and/or the at least one protective conductor contact. Furthermore, it can be provided that the at least one control contact is smaller and/or shorter or has a smaller spring travel than the power contacts. This ensures that a connection established via the at least one control contact is torn off before a connection at the power contacts or at least one protective conductor contact would be torn off.

In the vehicle contact unit, it can be provided in particular that the corresponding contacts are designed to be resilient, with the corresponding spring travels being different, in order to ensure that the corresponding connections break off at different times during a relative movement of the vehicle contact unit to the ground contact unit.

In principle, it can be provided that the at least one protective conductor contact loses contact last during a relative movement of the vehicle contact unit to the ground contact unit. In other words, the contact via the at least one protective conductor contact breaks off last. For this purpose, it can be provided, among other things, that the at least one protective conductor contact is designed to be larger than the at least one control contact and/or the power contacts.

It can also be provided that the at least one protective conductor contact of the vehicle contact unit, in particular the center of the at least one protective conductor contact, is arranged on a circular line with a radius that is larger than a radius of a circular line on which the at least one protective conductor is located - Contact of the ground contact unit is arranged, in particular the center of the at least one protective conductor contact. Alternatively, it can be provided that the at least one protective conductor contact of the ground contact unit, in particular the center of the at least one protective conductor contact, is arranged on a circular line with a radius that is larger than a radius of a circular line on which the at least one protective conductor contact is located. Contact of the vehicle contact unit is arranged, in particular the center of the at least one protective conductor contact. This has to The result is that the connection via the protective conductor contacts is the last to break during a relative movement of the vehicle contact unit to the ground contact unit.

In principle, the respective protective conductor contact can be arranged on a circular line that has a different radius than neighboring power contacts and/or control contacts.

The object is further achieved according to the invention by a system for establishing a conductive connection, the system having a vehicle contact unit with several contacts, which include at least one protective conductor contact, power contacts and at least one control contact for detecting contact. The system also has a ground contact unit with a plate-shaped base body and a plurality of contacts, which are arranged on a loading surface of the base body and include at least one protective conductor contact, power contacts and at least one control contact for detecting contact. The at least one protective conductor contact is hard-wired, i.e. that of the vehicle contact unit and that of the ground contact unit. The respective power contacts, i.e. those of the vehicle contact unit and those of the ground contact unit, are assigned to at least one potential level. The respective at least one control contact, i.e. that of the vehicle contact unit and that of the ground contact unit, is designed separately from the power contacts and separately from the at least one protective conductor contact. The vehicle contact unit can be moved translationally and/or rotationally in a plane parallel to the loading area. The system includes a monitoring circuit and a signal generator. In addition, the system is set up to apply a control signal to at least one control contact of the ground contact unit or the vehicle contact unit by means of the signal generator. The system is also set up to detect contacting of the ground contact unit by means of the monitoring circuit, which is set up to receive and evaluate the control signal generated by the signal generator, which in the contacted state via the at least one control contact of the vehicle contact unit and / or the at least one control contact of the ground contact unit running. With the corresponding system, it can therefore be determined whether the corresponding contact is present when a conductive connection is established, in particular with regard to the Position and orientation by the corresponding control signal passing through at least one of the control contacts and being evaluated accordingly.

One aspect provides that the contacts of the ground contact unit and the contacts of the vehicle contact unit are designed such that a connection via the protective conductor contact of the ground contact unit and the protective conductor contact of the vehicle contact unit remains when the connections via the power contacts during a relative movement of the vehicle contact unit to the ground contact unit have already been torn off, in particular due to a relative movement of the vehicle contact unit to the ground contact unit. In particular, a relative displacement of the vehicle contact unit to the ground contact unit is determined, which is perpendicular to the contacting direction, provided that this results in the connection established via the protective conductor contact breaking off.

A further aspect provides that the at least one control contact of the ground contact unit and/or the at least one control contact of the vehicle contact unit are or is designed such that a connection via the control contact of the ground contact unit and the control contact of the vehicle contact unit is broken during a relative movement of the vehicle contact unit to the ground contact unit before the connections via the power contacts are broken. For this purpose, the corresponding control contact can, for example, be made smaller in terms of area than the other contacts. In any case, it is ensured that the monitoring circuit first detects that the connection running via the control contact is no longer present, whereby the monitoring circuit can correspondingly control a shutdown device, which, for example, switches the power contacts potential-free.

Furthermore, the object is achieved according to the invention by a method for establishing a conductive connection between a ground contact unit and a vehicle contact unit. The vehicle contact unit has several contacts, which include at least one protective conductor contact, power contacts and at least one control contact for detecting contacting. The ground contact unit has a plate-shaped base body and a plurality of contacts which are arranged on a loading surface of the base body and at least one protective conductor contact, power contacts and at least one Include control contact for detecting contact. The at least one protective conductor contact is hard-wired. The respective power contacts are assigned to at least one potential layer, with the respective at least one control contact being designed separately from the power contacts and separately from the at least one protective conductor contact. The vehicle contact unit can be moved translationally and/or rotationally in a plane parallel to the loading area. The procedure includes the following steps:

- Applying a control signal to the at least one control contact of the ground contact unit or the vehicle contact unit and

Measuring whether the control signal is transmitted via a continuous connection that includes at least the control contact of the ground contact unit and/or the control contact of the vehicle contact unit.

In particular, the continuous connection can be provided between the control contact of the ground contact unit and the control contact of the vehicle contact unit. Alternatively, however, it can also be provided that, for example, the control contact of the ground contact unit forms a continuous connection with the protective conductor contact of the vehicle contact unit, with a continuous connection also being established. In a specific embodiment, this positioning also represents a desired contacting of the ground contact unit, in which a charging current can be released, which can flow via the corresponding power contacts in order to charge the battery of the vehicle.

One aspect provides that a contact area of the vehicle contact unit on the ground contact unit is identified by rotating the vehicle contact unit relative to the ground contact unit and/or switching through several control contacts of the ground contact unit individually and/or in groups. Several control contacts can be provided on the ground contact unit, which are switched through individually or in groups, for example, in order to determine whether there is a conductive connection via one of the control contacts, which are switched through accordingly. In this way, a position of the vehicle contact unit on the ground contact unit can first be roughly determined. A further aspect provides that an orientation of the vehicle contact unit relative to the ground contact unit is identified by applying different control signals to at least two control contacts of the ground contact unit or the vehicle contact unit. After a corresponding contact of the ground contact unit has been identified by the vehicle contact unit, in particular also the position of the contact area, the relative orientation can be determined. For this purpose, two different control signals are placed on two control contacts that are in the contact area. This can then be used to determine what the corresponding orientation of the vehicle contact unit is relative to the ground contact unit. Based on the recorded orientation, the corresponding power contacts can then be connected to specific potential levels to ensure an optimal charging process.

In addition, it can be provided that a cleaning check is carried out by applying a low protection voltage to the at least one control contact of the ground contact unit, with an insulation check being carried out between two contacts of the ground contact unit. Here it can be determined whether the insulation distance between two contacts is maintained, i.e. whether there is no contamination that would prevent this.

In principle, contact protection monitoring can be carried out to ensure that unintentional contact with accessible contacts is possible. Touch protection monitoring is carried out continuously during conductive charging. In addition, it can also be provided that the contact protection monitoring is carried out immediately before the charging process.

For this purpose, for example, it is provided that during the continuous touch protection monitoring, the respective switching positions of the contact switches are monitored, which are assigned to the power contacts which are not contacted. These are the power contacts that do not belong to a subset of the contacted contacts, which is why they are accessible from outside. The subset of contacted contacts corresponds to the contact area. The subset of the multiple contacts is therefore assigned to a contacting area of the loading area, which is formed by a component of the vehicle contact unit is covered when a conductive connection is established between the ground contact unit and the vehicle contact unit. The corresponding subset, i.e. the number of multiple contacts that are in the contacting area, depends on the size of the ground contact unit and/or the size of the corresponding component of the vehicle contact unit, which interacts with the contacts of the ground contact unit for the conductive connection, for example a connector of the vehicle contact unit .

The accessible contacts can also be referred to as exposed contacts because they are not covered by the vehicle contact unit when the conductive connection is present. The touch protection monitoring via the switching positions of the contact switches checks whether the corresponding power contacts are switched potential-free, as is intended for the exposed power contacts, i.e. the power contacts that do not form the conductive connection with the vehicle contact unit.

Alternatively or additionally, the continuous contact protection monitoring can consist of continuously monitoring whether the conductive connection that has already been established is maintained or whether the conductive connection that has been established has been broken. For this purpose, it may be sufficient if at least one of the contacts in the subset is checked because it had previously been contacted. In principle, the at least one contact of the subset that is used for the continuous touch protection check can be the control contact through which the control signal is passed, which is monitored accordingly.

The touch protection monitoring can be carried out using the monitoring circuit, which monitors the switching position of the contact switches and/or the continuous contacting of the corresponding contact of the subset, i.e. that of the control contact.

In an extreme example, it can be provided that all contacts of the ground contact unit are occupied, so that there are no exposed contacts in the contacted state. Accordingly, the subset of the multiple contacts can correspond to all contacts of the ground contact unit. Typically, however, the ground contact unit has more contacts than the contacts that are used for conductive active connection between the ground contact unit and the vehicle contact unit are required. This ensures, among other things, that the vehicle does not have to come to a stop exactly over a specific area of the ground contact unit, which results in greater flexibility. The component of the vehicle contact unit that covers the contact area can be a movable part of the vehicle contact unit, for example a movable loading trunk or similar, which is moved starting from an underbody of the vehicle in the direction of the ground contact unit in order to establish the conductive connection. The movable part of the vehicle contact unit can also be generally referred to as a connector.

In principle, a defined control signal can be fed in via the at least one control contact of the vehicle contact unit or the ground contact unit, which interacts with an associated contact of the other unit, for example a control contact, whereby a circuit is closed in which the corresponding control signal can be evaluated.

If two control contacts are provided on the vehicle contact unit and/or the ground contact unit, which are also supplied with different control signals, the orientation of the vehicle contact unit with respect to the ground contact unit can be determined when the conductive connection is present, i.e. the contacting orientation. Regardless of this, it is possible to form two channels with two control contacts, which creates appropriate redundancy.

The control signal can be a safety extra-low voltage.

In particular, the contacts are designed and arranged in such a way that at least two control contacts of the vehicle contact unit and/or two control contacts of the ground contact unit are always part of the contacted contacts in a contact area.

The respective contacts are also arranged and dimensioned in such a way that there is no short circuit when there is contact. This also applies in the event that the vehicle contact unit shifts relative to the ground contact unit, in particular in the contacting plane. Further advantages and properties of the invention result from the following descriptions and drawings, to which reference is made. Shown in the drawings:

1 shows a schematic overview of a system according to the invention with a charging infrastructure according to the invention and a vehicle contact unit according to the invention,

2 shows a schematic top view of a ground contact unit of a charging infrastructure according to the invention according to one embodiment,

3 shows a schematic top view of a ground contact unit of a store infrastructure according to the invention according to a second embodiment,

Figure 4 shows a schematic representation of the electrical connection of the power contacts in a charging infrastructure according to the invention, and

Figure 5 shows a schematic overview of a process that represents a method according to the invention for establishing a conductive connection between a ground contact unit and a vehicle contact unit.

1 shows a system 10 which shows an electrical charging infrastructure 12 and an at least partially electrically operated vehicle 14. The system 10 can also be referred to as a vehicle battery charging system.

The vehicle 14 has a vehicle contact unit 16, which can establish a conductive connection with a ground contact unit 18 of the electrical charging infrastructure 12 in order to charge a battery of the vehicle 14, not shown here.

The electrical charging infrastructure 12 has a monitoring circuit 20 and a shutdown device 22, which can be completely integrated in the ground contact unit 18. Alternatively, the monitoring circuit 20 can be arranged partly in the ground contact unit 18 and partly in a monitoring unit 24 which is designed separately from the ground contact unit 18. Furthermore, can It can be provided that the monitoring circuit 20 and the shutdown device 22 are both arranged completely in the separately designed monitoring unit 24.

The separately designed monitoring unit 24 is therefore optional, which is why it is shown in dashed lines in Figure 1. Likewise, the monitoring circuit 20 and the shutdown device 22 are shown in dashed lines, since their respective positions can be different depending on the embodiment. In any case, the separately designed monitoring unit 24 would be electrically connected to the ground contact unit 18, as indicated in Figure 1.

Alternatively, it can also be provided that the monitoring circuit 20 and/or the shutdown device 22 are provided on the vehicle side.

In Figure 2, the ground contact unit 18 of the charging infrastructure 12 is shown in a top view according to an embodiment.

The ground contact unit 18 has a plate-shaped base body 26 which has a loading surface 28 which is exposed before the conductive connection is established. The loading area 28 is an exposed loading area when the contact between the ground contact unit 18 and the vehicle contact unit 16 is made.

However, the loading area 28 can in principle be covered by a cover (not shown here) when not in use, so that the loading area 28 is protected from environmental influences, among other things. The corresponding cover can be removed manually or automatically, making the loading area 28 freely accessible.

Several contacts 30 are provided on the loading surface 28, which are different types of contacts.

In any case, the contacts 30 include, among other things, several power contacts 32, which are used to charge the battery of the vehicle 14. When charging the vehicle 14, in particular when charging the battery of the vehicle 14, a charging current flows through at least some of the power contacts 32. The corresponding power contacts 32 are for this purpose basically assigned to at least one potential layer 34, as will be explained below.

In the embodiment shown, the ground contact unit 18 is designed as a three-phase ground contact unit 18, which means that the individual power contacts 32 can be assigned to four different potential positions 34, namely the neutral position N and the phase positions L1, L2 and L3. The neutral position N is also referred to as the neutral conductor. These are therefore the corresponding potential levels N, P1, P2 and P3.

As can be seen from Figure 2, a corresponding three-phase connection 35 is therefore provided, in particular at the ground contact unit 18.

The power contacts 32 are therefore divided into power contact levels P1, P2, P3, P4 or assigned to the power contact levels, which are also referred to as “pin layers”.

In this respect, there are four types of power contacts 32, namely first power contacts 32-1, which are assigned to the first power contact level P1, second power contacts 32-2, which are assigned to the second power contact level P2, third power contacts 32-3, which are assigned to the third power contact level P3 are, as well as fourth power contacts 32-4, which are assigned to the fourth power contact level P4. This is clear from Figure 4, which will be referred to below when the interconnection of the power contacts 32 is described.

2 already shows that the four types of power contacts 32 are arranged in a rectangle, in particular in a rectangle on the loading area 28.

In the exemplary embodiment shown, the first power contact 32-1 is provided in an upper right corner of the rectangle, whereas the second power contact 32-2 is provided in the lower right corner of the rectangle. The third power contact 32-3 is provided in a lower left corner of the rectangle, whereas the fourth power contact 32-4 is provided in an upper left corner of the rectangle. In this respect, the four types of power contacts 32 together form the rectangle in the corresponding plane. In addition to the power contacts 32, the contacts 30 also include at least one protective conductor contact 36, i.e. a PE contact. In the embodiment shown in Figure 2, several protective conductor contacts 36 are provided, which are arranged separately and insulated from the power contacts 32 on the loading surface 28.

Furthermore, it can be seen from the embodiment shown in FIG. 2 that the protective conductor contacts 36 are each arranged in the center of the rectangles.

The rectangles are in particular designed as squares, so that the protective conductor contact 36 arranged in the center is at the same distance from each of the power contacts 32. In this respect, a centered square pattern is provided in FIG. 2 with regard to the power contacts 32 and the protective conductor contacts 36.

As an alternative to the embodiment shown in Figure 2, the ground contact unit 18 can have a continuous protective conductor level 38, which therefore essentially corresponds to the area of the base body 26 or the base area of the loading area 28, as shown in Figure 3.

The individual power contacts 32 then break through the corresponding protective conductor level 38, with the power contacts 32 each being arranged in isolation from the protective conductor level 38, for example by annular insulating sections 39 which isolate the power contacts 32 from the protective conductor level 38.

In addition, the contacts 30 can in principle include at least one control contact 40, which is used to carry out a contact check, i.e. to determine whether the vehicle contact unit 16 contacts the ground contact unit 18, which will be discussed below.

In the embodiments shown in Figures 2 and 3, several control contacts 40 are provided.

In principle, the control contacts 40 and/or the protective conductor contacts 36 can be designed as magnetic contacts 41, i.e. they can be magnetized. This makes it possible for the conductive connection produced to only take place in a defined manner, namely in such a way that at least one magnetic Contact 41 of the vehicle contact unit 16 couples to a magnetic contact 41 of the ground contact unit 18.

The defined connection is ensured because the magnetic contacts 41 are each arranged centrally in an assigned rectangle, in particular a square, in the corners of which a type of power contact 32 is provided, i.e. a first power contact 32-1, a second power contact 32- 2, a third power contact 32-3 and a fourth power contact 32-4. Consequently, either a protective conductor contact 36 or a control contact 40 can be provided in the center of the respective rectangle.

In particular, the contacts 30 are basically distributed on the loading area 28 and arranged relative to one another in such a way that at least two control contacts 40 lie in a contacting area A of the loading area 28, which is covered by the vehicle contact unit 16 when the conductive connection is established. The orientation in which the ground contact unit 18 was contacted can then be determined via the two control contacts 40 in the contacting area A.

By knowing the geometry of the vehicle contact unit 16, it can also be determined which contacts 30 have been contacted, i.e. which of the contacts 30 belong to the subset of the contacted contacts 30 that lie in the contacting area A of the loading area 28.

Based on this information, the corresponding power contacts 32 can then be switched in order to assign or connect a specific potential level 34 to the different power contact levels P1 to P4.

4 shows, using the example of an embodiment, how the power contacts 32 are connected. This basically applies to the connection of the power contacts 32 of the vehicle contact unit 16 as well as to the connection of the power contacts 32 of the ground contact unit 18.

The individual power contacts 32 can each be connected to a corresponding power contact level P1 to P4 via contact switches 42, so that the individual power contacts 32 can be switched on or off via the contact switches 42. This makes it possible that only the Power contacts 32 are connected to a corresponding potential layer 34, which lie in the contact area A, so that exposed power contacts 32 are potential-free.

4 also shows that the respective contact switches 42 are designed as mirror contacts, so that the contact switches 42 have a main contact 44 and a monitoring contact 46. Due to the design as a mirror contact, it is ensured that the main contact 44, which functions as a relay, is mechanically coupled to the monitoring contact 46, so that the respective switching positions of the main contact 44 and the monitoring contact 46 are mutually dependent or dependent on one another. However, the main contact 44 and the monitoring contact 46 are galvanically isolated from one another, so that both contacts 44, 46 are not assigned to a common circuit. Rather, both contacts 44, 46 are assigned to different circuits that are independent of one another and are also galvanically isolated from one another.

In this respect, there is no switching position of the contact switch 42 in which a closed circuit is formed in which both the main contact 44 and the monitoring contact 46 are integrated, so that a current could flow via both contacts 44, 46 of the contact switch 42. The main contact 44 is, as shown in Figure 4, designed as a normally open contact, i.e. a NO contact, whereas the monitoring contact 46 is designed as a normally closed contact, i.e. an NC contact.

4 therefore shows the initial position of the contact switches 42, since the contact switches 42 are each in a corresponding switching position in which the main contacts 44 are open, so that no current flow to the power contacts 32 is possible. In other words, the power contacts 32 are not connected to any potential layer 34, which ensures protection against contact.

The corresponding contact protection can be monitored by the monitoring circuit 20 monitoring, among other things, the respective switching position of the monitoring contacts 46 of the corresponding contact switches 42. The monitoring takes place at least with the contact switches 42, which are assigned to power contacts 32, which are not contacted when there is a conductive connection between the ground contact unit 18 and the vehicle contact unit 16, i.e. with power contacts 32, which are not part of the subset of the several contacts 30 of the ground contact unit 18 belong who have been contacted.

The monitoring circuit 20 controls the shutdown device 22 if the monitoring circuit 20 determines that there is an incorrect switching position in one of the monitoring contacts 46, which has the result that one of the main contacts 44 also has an incorrect switching position, since the monitoring contacts 46 and the main contacts 44 are mechanically coupled to each other.

The incorrect switching position corresponds to an open switching position of the monitoring contact 46, which is accompanied by a closed switching position of the assigned main contact 44, which would mean that a freely accessible power contact 32 would be assigned to a potential position 34, although this is not desired since the corresponding power contact 32 is exposed.

The shutdown device 22 changes its state due to the control by the monitoring circuit 20, which can be accompanied by a complete shutdown or a complete separation. In other words, the shutdown device 22 can be designed in such a way that a galvanic isolation of all power contacts 32 is carried out, whereby all power contacts 32 would be switched potential-free.

In this respect, the shutdown device 22 can include a main switch 46 or a contactor, which carries out the corresponding galvanic isolation.

Alternatively, the switch-off device 22 can include an electronic power control 50, which is intended to correspondingly reduce the voltage assigned to the potential level 34, so that the applied voltage is limited to a non-critical value, thereby ensuring contact protection. In other words, the respective power contact 32, which is coupled to the incorrectly closed main contact 44 of the contact switch 42, has such a low voltage that there is no danger. In addition, it can be seen from Figure 4 that an input interface 52 is provided, which is assigned to the connection 35 and the potential layers 34.

Furthermore, an output interface 54 is provided, which is connected to the power contacts 32, in particular the power contact levels P1 to P4.

In addition, a switching unit 56 is provided, which is provided between the input interface 52 and the output interface 54.

The switching unit 56 has a plurality of switches 58, which are basically set up to selectively switch the power contacts 32 belonging to a power contact level P1 to P4 together between a first potential position 34 and a second potential position 34, for example between the neutral position N and the first phase L1.

This happens in particular depending on the orientation of the vehicle contact unit 16 to the ground contact unit 18 determined via the control contacts 40.

The switching unit 56 ensures, for example, that at least the first power contacts 32-1, i.e. the power contacts 32 that are assigned to the first power contact level P1, are either connected to the first potential position 34 (neutral position N) or to the second potential position 34 (first phase position L1). are connectable.

4, the switching unit 56 is designed in such a way that all power contact levels P1 to P4, i.e. the respective power contacts 32, can be connected in groups to each of the existing potential layers 34, so that maximum flexibility is guaranteed.

4 shows the four different types of power contacts 32, i.e. a first power contact 32-1, a second power contact 32-2, a third power contact 32-3 and a fourth power contact 32-4. In other words, power contacts 32 are shown, which correspond to the first power contact level P1, the second power contact level level P2, the third power contact level P3 and the fourth power contact level P4 are assigned or are connected to them via the corresponding contact switches 42.

In principle, the switches 58 - like the contact switches 42 - can also be designed as mirror contacts, so that the switches 58 have a main contact 60 and a monitoring contact 62.

In contrast to the power contacts 32, the at least one protective conductor contact 36 is hard-wired, which means that the at least one protective conductor contact 36 or the protective conductor level 38 is fixed, i.e. cannot be connected to one of the potential layers 34.

This applies equally to the control contacts 40, which are also hard-wired.

As already explained above, the at least one control contact 40 is provided to carry out a contact check, i.e. to determine whether the vehicle contact unit 16 has contacted the ground contact unit 18.

In particular, the contacts 30 are basically distributed, dimensioned and/or arranged relative to one another in such a way that at least two control contacts 40 lie in the contact area A, which is covered by the vehicle contact unit 16 when the conductive connection is established, as shown in FIGS. 2 and 3 can be removed.

5 shows a sequence that shows which steps are carried out to initiate and end a charging process.

To prepare for the charging process, a self-test of the power contacts 32 can first be carried out to ensure that the contact switches 42 of all power contacts 32 are open. This can be done at the beginning to ensure that the ground contact unit 18 and/or the vehicle contact unit 16 is basically in a state to be able to carry out a charging process at all. For this purpose, the positions of the contact switches 42, in particular the monitoring contacts 46, can be monitored by means of the monitoring circuit 20.

In addition, the preparation phase can include a compatibility check, in which communication takes place between the ground contact unit 18 and the vehicle contact unit 16 of the vehicle in order to determine whether the two contact units 16, 18 can even carry out a charging process with one another. Corresponding signals are exchanged with one another in order to determine whether the contact units 16, 18 are compatible with one another.

Subsequently, positioning can take place during the preparation phase, in which the vehicle 14 is positioned via the ground contact unit 18 or in relation to it by outputting appropriate signals, so that, for example, a driver of the vehicle 14 parks the vehicle 14 as precisely as possible via the ground contact unit 18 , whereby a conductive connection can be established. The signals can be optical and/or acoustic signals. In the case of a vehicle that is at least partially operated autonomously, positioning can also take place automatically. In any case, this makes it possible to minimize the size of the ground contact unit 18.

The vehicle 14 or the vehicle contact unit 16 will then send a charging request to the electrical charging infrastructure 12, in particular the ground contact unit 18. The electrical charging infrastructure 12 processes the charging request accordingly. If the result is positive, this will be communicated to the vehicle 14 or the vehicle contact unit 16, whereupon the charging process could be initiated.

For this purpose, the conductive connection between the vehicle contact unit 16 and the ground contact unit 18 is first established by moving at least one component of the vehicle contact unit 16, for example a connector, in the direction of the ground contact unit 18, whereby it comes to rest on the loading area 28 of the ground contact unit 18 in certain areas, so that at least a subset of the multiple contacts 30 of the ground contact unit 18 is contacted. In order to determine this, a contact check is carried out, in which it is determined whether contacts 30 of the ground contact unit 18 are contacted.

The contact check is carried out via the control contacts 40. For this purpose, at least one control signal, for example a low protection voltage, is applied to the control contacts 40, in particular to at least one of the control contacts 40. The control signal can be generated by a signal generator 64, which is provided on the vehicle side, for example as Part of the vehicle contact unit 16. Alternatively, the signal generator 64 can be provided on the infrastructure side, for example as part of the charging infrastructure 12.

In addition, it is measured whether the control signal is transmitted via a continuous connection that includes at least the control contact 40 of the ground contact unit 18 and/or the control contact 40 of the vehicle contact unit 16 to which the control signal has been applied. The monitoring circuit 20 can be used accordingly for this purpose.

In addition, it can be determined which of the corresponding contacts 30 are contacted by switching the control contacts 40 through individually and/or in groups. If it is determined that there is a continuous connection on one of the control contacts 40, it has been determined that the corresponding control contact 40 is contacted.

By specifically switching on the control contacts 40, the contact area A of the vehicle contact unit 16 on the ground contact unit 18 can be identified.

The environment of the determined control contact 40 can then also be switched on in order to check which (adjacent) control contacts 40 have been contacted.

This ensures that a placement position of the vehicle contact unit 16 is determined, since based on the knowledge of the contacted control contacts 40, it can also be determined which other contacts 30 are contacted. For this purpose, use is made of the fact that the magnetic contacts 41 are provided, whereby the vehicle contact unit 16 only contacts the ground contact unit 18 in a defined manner, namely in such a way that there is a coupling via two magnetic contacts 41, which is also referred to as “snapping”.

The control contacts 40 can also carry different control signals, whereby it can also be determined what the contacting orientation of the vehicle contact unit 16 is in relation to the ground contact unit 18. This can also be done using the monitoring circuit 20.

The charging infrastructure 12 and/or the vehicle contact unit 16 are/is accordingly set up to detect a contacting orientation of the vehicle contact unit 16 on the loading area 28 by means of the at least two control contacts 40.

Depending on the contacting check carried out and the contacting position determined, i.e. the placement position, as well as the optionally determined contacting orientation, the contacted power contacts 32 could then be connected to specific potential positions 34, in particular via the corresponding switching unit 56.

During the checking phase, however, a protective conductor check can still take place, in which a test current is passed over at least one contact 30 of the several contacts 30 in order to determine a contact quality of the existing conductive connection between the vehicle contact unit 16 and the ground contact unit 18.

For this purpose, the vehicle 14 can include a current generator or a signal generator, which provides the test current, which is conducted via one of the contacts of the vehicle contact unit 16 to a contact 30 of the contacts 30 of the ground contact unit 18 coupled thereto.

For example, one of the power contacts 32 can be used, which is coupled to a corresponding power contact 32 of the vehicle contact unit 16, the corresponding power contact 32 of the ground contact unit 18 being switched to the protective conductor level, which corresponds to the level of the protective conductor contact 36. A relay can be provided for this purpose, via which the corresponding contact 30 is connected to the protective conductor level.

A resistance can then be measured to determine the contact quality. The measured resistance should not exceed a resistance value of 0.1 Q, so that a protective conductor resistance threshold of 0.1 Q is provided. The test current used should have a current strength of at least 200 mA. Alternatively, it can also be provided that the test current is provided by the ground contact unit 18.

A further step provides that an insulation check is carried out during the check in order to determine that there are no leakage or secondary currents or the like between contacts 30 or other areas of the ground contact unit 18. In principle, the insulation test can be carried out between two contacts 30 by applying a test voltage and measuring an insulation resistance, which is compared with a predetermined insulation resistance threshold. For example, the test voltage is at least 500 V. The insulation resistance threshold is, for example, 0.25 MQ.

The two contacts 30 that are used for the insulation check can be adjacent contacts on the loading surface 28, in particular two contacts 30 of the subset of the contacts 30 that are contacted when the conductive connection is present. An (unintentional) conductive connection is most likely to occur between adjacent contacts 30, for example via an object, dirt or moisture. In particular, the insulation check is carried out between two power contacts 32. Alternatively or additionally, it can be provided that the insulation check is carried out between at least one line contact 32 and the at least one protective conductor contact 36. The insulation check can also be carried out between at least one line contact 32 and the control contact 40.

During the insulation check, the insulation from a contact 30 of the subset to a point on the loading surface 28 of the base body 26 can also be measured. In principle, it can be provided that the insulation check is only carried out if it has previously been determined that at least a subset of the several contacts 30 are contacted at all, i.e. there is a conductive connection.

In addition, the protective conductor check can only be carried out if it has previously been determined that there is a conductive connection, i.e. at least the subset of the several contacts 30 is contacted. In addition, the protective conductor check can only be carried out if the insulation check has been carried out successfully beforehand.

The insulation check can also be viewed as part of a cleaning check, in which a low protection voltage is applied to the at least one control contact 40 of the ground contact unit 18. The insulation check between two contacts 30 of the ground contact unit 18 is then carried out.

After the verification has been carried out and all verification steps have been successfully completed, the loading process can begin.

As already explained previously, the power contacts 32, which do not belong to the subset of the contacted contacts 30, have already been switched potential-free via the contact switches 42, which was also checked during the self-test during preparation.

In this respect, only the power contacts 32 of the corresponding potential position 34, which belong to the subset of the contacted contacts 30, are switched on.

The information that was obtained during the contact check is used here, since only the power contacts 32 are connected to a potential position 34 via the assigned contact switches 42, which are actually contacted in order to ensure contact protection. This information is obtained based on the recorded landing position. The respective potential position 34 is also selected based on the contact orientation determined during the contact check.

As explained above, the switching unit 56, in particular the switches 58, is set up in such a way that the power contact levels P1, P2, P3, P4 can be connected to the different potential positions 34, for example the neutral position N or one of the phase positions L1, L2, L3 . In this respect, it can be used to set whether the neutral position N or one of the phase positions L1, L2, L3 is present in the upper right corner of a respective rectangle.

This can apply in an analogous manner to all corners of the rectangle, provided that the switching unit 56 is designed as shown in FIG. Therefore, the respective potential position of the corners of the rectangle can be adjusted based on the detected contacting orientation.

In particular, the power contact levels P1, P2, P3, P4 are first connected to the different potential layers 34 before the correspondingly contacted power contacts 32 are connected to the power contact levels P1, P2, P3, P4 via the contact switches 42, i.e. are connected to a potential.

After the electrical connection between the contacted power contacts 32 and the corresponding potential positions 34 has been established, a charging current can flow from the ground contact unit 18 via the vehicle contact unit 16 into the battery of the vehicle 14, whereby the battery is charged accordingly.

Continuous touch protection monitoring takes place during the charging process, as already explained. This determines whether only the contacted power contacts 32 of a corresponding potential position 34 are actually connected.

Furthermore, it is checked whether the existing contact breaks off during the charging process by continuously monitoring a contact 30 of the subset of contacted contacts, namely the control contact 40.

Among other things, it is provided that the at least one control contact

40 has a smaller area than the at least one protective conductor contact 36 and/or as one of the power contacts 32, in particular as each of the power contacts 32. In this respect, the connection via the at least one control contact 40 would first be broken off before the connections via the power contacts 32 and/or the connection via the protective conductor contact 36 would be torn off or torn off.

If it is determined that contact protection is no longer guaranteed, i.e. the connection via the at least one control contact 40 is broken, the shutdown device 22 is controlled by the monitoring circuit 20, whereby either the main switch 48 is opened in order to carry out a galvanic isolation, and / or the electronic power control 50 regulates the corresponding potential down until a non-critical voltage value has been reached. The non-critical value can be a voltage that is harmless, in particular a voltage below 25 V AC, i.e. 25 Vac, or 60 V DC, i.e. 60 Vdc.

Alternatively or in addition to the smaller area of the at least one control contact 40, it can also be provided that the control contacts 40 are designed with a smaller spring travel than the power contacts 32 and / or the at least one protective conductor contact 36, in particular the control contacts 40 of the vehicle contact unit 16. Likewise The control contacts 40 can be shorter than the power contacts 32 and/or the at least one protective conductor contact 36.

In any case, this ensures that when the vehicle contact unit 16 is displaced relative to the ground contact unit 18, the connection established via the at least one control contact 40 is initially torn off before the connection via the power contacts 32 and/or the connection via the protective conductor contact 36 is torn off. The power contacts 32 can thus be actively switched to potential-free or the voltage level can be actively reduced before their connection breaks and/or an arc occurs.

The tearing of the conductive connection is detected in particular in a direction that is perpendicular to the contacting direction, i.e. in the plane in which the contacting is present. It is therefore determined whether the vehicle contact unit 16 slips or shifts relative to the ground contact unit 18, as a result of which the connection via the at least one control contact 40 breaks off, in particular first. If no unwanted tearing of the conductive connection is detected, the charging process is carried out until the end. The contact monitoring takes place continuously, as already explained above.

After the charging process has been completed, the conductive connection between the vehicle contact unit 16 and the ground contact unit 18 is actively separated.

For this purpose, the previously connected power contacts 32, which belong to the subset, are first switched potential-free by controlling the corresponding contact switches 42.

In addition, the shutdown device 22 can also be controlled accordingly, for example to carry out galvanic isolation via the main switch 48. This creates redundancy. In addition, it can be checked again whether the power contacts 32 are all potential-free by monitoring the assigned monitoring contacts 46 via the monitoring circuit 20.

The conductive connection is then released by disengaging the vehicle contact unit 16 so that there is no longer any contact with the ground contact unit 18. The vehicle 14 can then leave the electrical charging infrastructure 12.

Finally, a new self-test can be carried out by determining whether all power contacts 32 are in their potential-free state, i.e. whether the assigned contact switches 42 are all in the non-current-carrying state, which is present when the corresponding main contacts 44 are opened or the monitoring contacts 46 are closed.

In principle, the self-test can of course also be carried out at other times. Self-tests can therefore be carried out at several times, for example cyclically, in order to continuously check the readiness of the electrical charging infrastructure 12, in particular that of the ground contact unit 18.

In this respect, it is ensured that the vehicle 14 can be efficiently charged electrically by making a conductive connection. At the same time Appropriate safety precautions are taken by checking whether the ground contact unit 18 is in a state that is suitable for a charging process.

The process shown in Figure 5 and the associated method can in principle be carried out by the electrical charging infrastructure 12, which is set up accordingly.

Basically, the vehicle contact unit 16 can be moved translationally and/or rotationally in a plane parallel to the loading area 28. The vehicle contact unit 16 can even be moved along the loading area 28, i.e. parallel to it, when the vehicle contact unit 16 rests on the loading area 28.

The translational and/or rotational relative movement of the vehicle contact unit 16 to the loading area 28 ensures that the contacts 30 of the vehicle contact unit 16 and the contacts 30 of the ground contact unit 18 can come into contact, i.e. overlap.

Claims

Patent claims

1. Charging infrastructure (12) for establishing a conductive connection with a vehicle contact unit (16), the charging infrastructure (12) comprising a ground contact unit (18) which has a plate-shaped base body (26) and a plurality of contacts (30) which are on a loading area (28) of the base body (26) are arranged, on which the vehicle contact unit (16) can come into contact, the plurality of contacts (30) having at least one protective conductor contact (36), power contacts (32) and at least one control contact (40). for detecting contact, wherein the at least one protective conductor contact (36) is hard-wired, the power contacts (32) being assigned to at least one potential layer (34), the at least one control contact (40) being separate from the power contacts (32). and is formed separately from the at least one protective conductor contact (36).

2. Charging infrastructure (12) according to claim 1, characterized in that at least two power contacts (32) are assigned to the same potential layer (34), in particular wherein several potential layers (34) are provided, with each potential layer (34) having at least two power contacts (32 ) assigned.

3. Charging infrastructure (12) according to claim 1 or 2, characterized in that the charging infrastructure (12) comprises a monitoring circuit (20) which is set up to monitor the contacting of the at least one control contact (40), in particular wherein the monitoring circuit (20 ) is set up to determine a placement position of the vehicle contact unit.

4. Charging infrastructure (12) according to one of the preceding claims, characterized in that the at least one control contact (40) has a smaller area than the at least one protective conductor contact (36) and / or than one of the power contacts (32), in particular as each of the power contacts (32).

5. Charging infrastructure (12) according to one of the preceding claims, characterized in that the plurality of contacts (30) comprise at least two control contacts (40), so that the charging infrastructure (12) is set up to have a contacting orientation by means of the at least two control contacts (40). Vehicle contact unit (16) on the loading area (28) to detect, in particular wherein the plurality of contacts (30) include two categories of control contacts (40) which differ in terms of control signals used which are passed over the control contacts (40).

6. Charging infrastructure (12) according to one of the preceding claims, characterized in that the at least one protective conductor contact (36) is formed by a continuous surface which provides a protective conductor level (38) which is formed by the power contacts (32) and / or the at least one control contact (40) is broken.

7. Vehicle contact unit (16) for establishing a conductive connection with a ground contact unit (18), wherein the vehicle contact unit (16) has a plurality of contacts (30) which can come into contact with a loading area (28) of the ground contact unit (18), the Vehicle contact unit (16) can be moved translationally and/or rotationally in a plane parallel to the loading area (28), the plurality of contacts (30) having at least one protective conductor contact (36), power contacts (32) and at least one control contact (40) for detection a contacting, wherein the at least one protective conductor contact (36) is hard-wired, the power contacts (32) being assigned to at least one potential layer (34), the at least one control contact (40) being separate from the power contacts (32) and separately to which at least one protective conductor contact (36) is formed.

8. Vehicle contact unit (16) according to claim 7, characterized in that the contacts (30) are designed such that the at least one control contact (40) opens earlier than the power contacts (32) when the vehicle contact unit (16) moves relative to the ground contact unit (18). ) and/or the at least one protective conductor contact (36) loses contact with the ground contact unit (18) and/or that the at least one protective conductor contact (36) moves later than that when the vehicle contact unit (16) moves relative to the ground contact unit (18). Power contacts (32) lose contact with the ground contact unit (18).

9. System (10) for establishing a conductive connection, wherein the system (10) has a vehicle contact unit (16) with a plurality of contacts (30), which has at least one protective conductor contact (36), power contacts (32). and at least one control contact (40) for detecting contact, the system (10) having a ground contact unit (18) with a plate-shaped base body (26) and a plurality of contacts (30) which are on a loading surface (28) of the base body (26 ) are arranged and comprise at least one protective conductor contact (36), power contacts (32) and at least one control contact (40) for detecting contact, the at least one protective conductor contact (36) being hard-wired, the respective power contacts ( 32) are assigned to at least one potential layer (34), the respective at least one control contact (40) being designed separately from the power contacts (32) and separately from the at least one protective conductor contact (36), the vehicle contact unit (16) being translational and / or rotatably movable in a plane parallel to the loading surface (28), the system (10) comprising a monitoring circuit (20) and a signal generator (64), the system (10) being set up to generate a control signal by means of the signal generator (64 ) to be applied to at least one control contact (40) of the ground contact unit (18) or the vehicle contact unit (16), and wherein the system (10) is set up to detect contacting of the ground contact unit (18) by means of the monitoring circuit (20), which is set up to receive and evaluate the control signal generated by the signal generator (64), which in the contacted state runs via the at least one control contact (40) of the vehicle contact unit (16) and / or the at least one control contact (40) of the ground contact unit (18).

10. System (10) according to claim 9, characterized in that the contacts (30) of the ground contact unit (18) and the contacts (30) of the vehicle contact unit (16) are designed such that a connection via the protective conductor contact (36) the ground contact unit (18) and the protective conductor contact (36) of the vehicle contact unit (16) remain in place if the connections via the power contacts (32) have already been broken during a relative movement of the vehicle contact unit (16) to the ground contact unit (18), in particular due to a Relative movement of the vehicle contact unit (16) to the ground contact unit (18).

11. System (10) according to claim 9 or 10, characterized in that the at least one control contact (40) of the ground contact unit (18) and / or the at least one control contact (40) of the vehicle contact unit (16) is or is designed such that a connection via the control contact (40) of the ground contact unit (18) and the control contact (40) of the vehicle contact unit (16) is established during a relative movement of the vehicle contact unit (16 ) to the ground contact unit (18) breaks off before the connections via the power contacts (32) break off.

12. A method for establishing a conductive connection between a ground contact unit (18) and a vehicle contact unit (16), the vehicle contact unit (16) having a plurality of contacts (30) which have at least one protective conductor contact (36), power contacts (32) and at least a control contact (40) for detecting contact, wherein the ground contact unit (18) has a plate-shaped base body (26) and a plurality of contacts (30) which are arranged on a loading surface (28) of the base body (26) and at least one protective conductor Contact (36), power contacts (32) and at least one control contact (40) for detecting contact, the at least one protective conductor contact (36) being hard-wired, the respective power contacts (32) having at least one potential layer (34). are assigned, the respective at least one control contact (40) being designed separately from the power contacts (32) and separately from the at least one protective conductor contact (36), the vehicle contact unit (16) being translational and/or rotational in a manner relative to the loading area ( 28) parallel plane is movable, the method comprising the following steps:

- Applying a control signal to the at least one control contact (40) of the ground contact unit (18) or the vehicle contact unit (16), and

Measuring whether the control signal is transmitted via a continuous connection that includes at least the control contact (40) of the ground contact unit (18) and/or the control contact (40) of the vehicle contact unit (16).

13. The method according to claim 12, characterized in that a contact area (A) of the vehicle contact unit (16) on the ground contact unit (18) is identified by rotating the vehicle contact unit (16) relative to the ground contact unit (18) and / or a plurality of control contacts ( 40) the Ground contact unit (18) can be switched through individually and/or in groups.

14. The method according to claim 12 or 13, characterized in that an orientation of the vehicle contact unit (16) relative to the ground contact unit (18) is identified by at least two control contacts (40) of the ground contact unit (18) or the vehicle contact unit (16) with different control signals be applied.

15. The method according to any one of claims 12 to 14, characterized in that a cleaning check is carried out by applying a small protection voltage to the at least one control contact (40) of the ground contact unit (18), with an insulation check between two contacts (30). the ground contact unit (18) is carried out.